Variegated banana losing variegation

Does any one know why my Ae Ae banana is losing its variegation?

When I bought it several months ago, all the leaves had great green and cream color, but now that its grown over 6 feet tall, all the variegation has disappeared from the leaves.

Its growing in amended, somewhat alkaline soil. Should I try to lower the ph?

Thanks!

How much light is it getting?
I’m wondering if they’re like crotons? Not enough light and they lose their color too.

CMC +fnord!